usb: musb: musb_cppi41: Workaround DMA stall issue during teardown

The DMA may hang up if a teardown is initiated while an endpoint is still
active (Advisory 2.3.27 of DA8xx errata).
To workaround this issue, add a delay before to initiate the teardown.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c
index 7b9a44dc1188fc5dd1763ebb6a3c35d32d6b0a5d..5a8a031485ea46df96eef77e11bcf599a905fa44 100644 (file)
--- a/drivers/usb/musb/da8xx.c
+++ b/drivers/usb/musb/da8xx.c
@@ -483,7 +483,7 @@ da8xx_dma_controller_create(struct musb *musb, void __iomem *base)
 
 static const struct musb_platform_ops da8xx_ops = {
        .quirks         = MUSB_INDEXED_EP | MUSB_PRESERVE_SESSION |
-                         MUSB_DMA_CPPI41,
+                         MUSB_DMA_CPPI41 | MUSB_DA8XX,
        .init           = da8xx_musb_init,
        .exit           = da8xx_musb_exit,
 

diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index 5b708be6d1d1d4293e04cc36bc4403ba1bff17e7..3e98d4268a6478a36348b7144dd38fe49167670b 100644 (file)
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -172,6 +172,7 @@ struct musb_io;
  */
 struct musb_platform_ops {
 
+#define MUSB_DA8XX             BIT(8)
 #define MUSB_PRESERVE_SESSION  BIT(7)
 #define MUSB_DMA_UX500         BIT(6)
 #define MUSB_DMA_CPPI41                BIT(5)

diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index 355655f8a3fbc9c4e3d8acd03eefa31a5736fb2f..e7c8b1b8bf2296229b2eef3343811e6cbbc9b317 100644 (file)
--- a/drivers/usb/musb/musb_cppi41.c
+++ b/drivers/usb/musb/musb_cppi41.c
@@ -571,6 +571,10 @@ static int cppi41_dma_channel_abort(struct dma_channel *channel)
                }
        }
 
+       /* DA8xx Advisory 2.3.27: wait 250 ms before to start the teardown */
+       if (musb->io.quirks & MUSB_DA8XX)
+               mdelay(250);
+
        tdbit = 1 << cppi41_channel->port_num;
        if (is_tx)
                tdbit <<= 16;